1977 Mercruiser 470 Problems - Please Help

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

Where would these 3 wires be located?

The switch goes into the 3 wires here, at the red plug. RED, GREEN, BLUE. No Black.
Is THIS what you mean? THESE 3 wires?

 

[Eric 3.7LX Alpha 1]

Re: 1977 Mercruiser 470 Problems - Please Help

Your black ground wire is on the solenoid (small stud on top).

Yes those wires on that red plug are to power the motor.

The red wire from the "red plug" is the same red wire on solenoid valve, and the same red wire you have loose still. Sends power up to the dash switch.

The blue wire from the "red plug" is the same blue wire on the solenoid valve. (small bottom stud). Receives power from the dash switch for UP

The green wire from the plug (I THINK) runs directly to the trim motor itself according to the wiring diagram. Receives power from the dash switch for DOWN

The small top stud on the solenoid is ground for the trim motor and the solenoid.

When the solenoid gets power to the small bottom stud (blue wire from the red plug), it connects together the two large studs (red and blue wire). This runs the motor in the up position. To test the trim motor, apply 12 volts to the right stud where the blue wire is and as long as there is good ground on the small stud the motor should work.


To me it looks like in this setup the solenoid will only work for the up and not the down. Down goes from the switch directly to the trim motor.

I Hope any of this helps you understand the circuit.

 

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

OK, hooked a wire from the batt to the RIGHT solenoid post (blue wire): NOTHING.

Hooked it to the BOTTOM post (also blue wire): NOTHING.

For sh*ts & giggles, touched it to the TOP post, and was treated to a wonderful Sparkler Show.

.... This means my pump's bad, or my solenoid, yeah?

 

[Eric 3.7LX Alpha 1]

Re: 1977 Mercruiser 470 Problems - Please Help

Well those are 3 different tests you performed....
Batt to right post blue wire bypasses the solenoid and tests the pump.

Bottom post tests the solenoid... even if the pump was dead, you should have heard a click from the solenoid, then had battery voltage on the right solenoid post you can use a multi meter or test light to confirm it.

The top post confirmed there is ground at that post and you created a short.... not a good one to do but it's ok.

So in my opinion, the solenoid and pump seem NG.

It's possible you have a dead solenoid and the black ground wire for the motor isn't getting good ground. Try removing the black ground wire and clean it well, and try the first test again. If no go then the motor is most likely also NG.

You may as well stop messing with the dash switch. Get the pump motor and solenoid going then continue with the rest.

 

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

Alright, thanks. I wont have the money for anything for a couple months...

 

[artificialreef]

Re: 1977 Mercruiser 470 Problems - Please Help

Didnt see anyone tell this gentleman to change his 13 year old impellar. Would be a shame to watch him get this motor running only to blow a head gasket. When i got my basket case home that sat for 3 years found a doughnut where the impellar was supposed to be and almost overheated her.

 

[stonyloam]

Re: 1977 Mercruiser 470 Problems - Please Help

Excellent point!!

 

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

Well... Got myself a new problem. I turn the steering wheel, and nothing happens.

... as for the propeller, it's all just fine. No problems on THAT front.

- there's a big red hose running from the steering assembly, back to an arm on the transom. The wheel turns a little, but very difficult. I cant turn the outdrive by hand, AT ALL...

The steering arm on the transom wont budge.

I took the out the bolt that connects the outdeive to the steering bar thing, and the outdrive moves freely. But the steering bar dights me, and doesnt want to move in nor out.

 

[stonyloam]

Re: 1977 Mercruiser 470 Problems - Please Help

Tilt trin should have no effect on the steering. You do not have a power steering pump on the engine, so no power steering.

 

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

So, is it a problem in the CABLES, or the Shaft-actuator-thing?

 

[stonyloam]

Re: 1977 Mercruiser 470 Problems - Please Help

Disconnect the shaft and see if the outdrive will swing back and forth, and turn the wheel to see if the actuator moves in and out. I am guessing that the outdrive will move and the cable will not.

 

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

I did that. The outdrive is free, but the shaft refuses to budge.

Bad cable, or bad shaft?

I cant find another shaft, everytime I do an online search, the results I get back are for power steering actuators, and look NOTHING like what i have.

 

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

OK, I just pulled the engine back out (god that SUCKS), so I could have more room to mess with the wiring and the steering bar-thing. I unscrewed the steering assembly, and hit it with a BIG HAMMER.... and a bunch of gold fell out.. well, it was FLAKE alright, but more ALUMINUM than Gold. So, somehow, something got chewed up inside there, and wouldnt let me turn the steering wheel... but NOW, all is well. I WD-40'd the sh*t outta it, and cleared the shrapnel outta the way.

But Now I have a whole new issue, that may be the reason why my TRIM doesnt work:

I have 4 wires, going to 2 Trim Limit switches (yes, I finally found the Trim Limit Switch). There's 1 on the Starboard side, and 1 on the Port side of the Outdrive. Both of them have 2 wires coming out. All 4 of these wires are shot to hell. Frayed, split, cut, you name it, all are bad. So I'm replacing them right now.

But Here's where I need help. I had a diagram with the trim limit switch in it, but it didnt have '2' switches.

I need a diagram to hook up the 4 wires of 2 trim limit switches. Anyone have that? Or am I wrong, and 1 is T. Limit, and 1 is T. Sender?

 

[stonyloam]

Re: 1977 Mercruiser 470 Problems - Please Help

Port is trim limit, starboard is trim sender (to trim gauge).

 

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

But how do I wire them?

There's a LONGER wire and a SHORTER wire in each one.

Where does each one go? (photos are preferrable to diagrams)

thanks

 

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

Well... Good news, Bad news:

1. Got the boat to the water today, to test it and make sure there'll be no problems when I go tubing tomorrow.

Well... didnt go as well as I'd Hoped:

Mercruiser 470 on the Water - YouTube

So, I need to sell my 4cyl, and get me a V6 truck to be able to haul this thing... I may even sell the boat. Kinda tired of screwing with it...

Trim still doesnt work, only 2 seats (as opposed to the 6 Original seats), water pump doesnt work (that sucks water out of the boat), it takes on water (SOMEWHERE...), and it dies after 10 minutes of playing.

Anyone think it's worth the $1400 I have invested in it? (even with ALL the problems listed above)

 

[dccordell]

Re: 1977 Mercruiser 470 Problems - Please Help

Alright, so let's address some of the issues you're having before you try to sell the boat.

The trim...
Maybe needs a new pump motor.
Either:
1) Tear down the pump motor, clean it, see if it is frozen, needs new brushes, is completely rusted out, etc.
2) Take a gamble and buy a used pump/motor on ebay (they show up all the time, I picked up one for around $80).

Also, you need to address the frayed wires on the trim limit switch on the drive. If those wires are completely jacked up, the switch on the dash won't work. Possibly need to replace the trim limit and trim sender switches on the drive.
Since jumping power to the pump motor fails, I'm thinking it is possibly frozen due to rust (mine was).

Steering...
It's not unusual for the steering bar to be froze up (mine was). Now that you've freed it, make sure to put some grease on the bar and move it in and out of the tube several times to get everything coated well with grease to prevent it from happening again.

Water pump (bilge pump)...
Well, those are fairly cheap and if the boat has been sitting long, not surprising it no longer works. Replace it.

Taking on water...
That could be caused by several things. First thing I would check is the bellows in the drive, they are likely cracked. Check all of your hoses, especially the sea water hose from the drive (comes from the transom assembly behind the motor).

Possible starter issues (loud, slow starts)..
Starter needs rebuilding, or a new one. It MUST be marine rated. There is an "aftermarket" that is popular with the 470s, although I don't know the part number off the top of my head.

I get the impression that you are looking for a boat that you can get on the water sooner, rather than later, and judging by the amount of work needed to get the motor/trim working, needed interior work, etc, you might be happier finding another boat closer to water-ready. Without seeing the interior, it's hard to tell how big of a project boat you've got yourself there.

As far as what it's worth... it's worth whatever somebody is willing to pay on any given day. I paid more for mine and ended up doing a complete restore on it, costing WAY more than the boat will ever be worth.

It all just depends on how much work you are willing to put into the boat, how soon you want to be on the water, and how much money you're willing to sink. One thing always leads to another with boats...

 

[stonyloam]

Re: 1977 Mercruiser 470 Problems - Please Help

I watched the vid. Need to give a little more throttle when you start. When it is warm, push in the throttle only button and give er about 1/3 throttle. Mine will not start with the throttle at idle, starts right up at 1/3 throttle. You will have to experiment a little to figure it out. Yeah boats are fun :facepalm:.

 

[Syrus54]

Re: 1977 Mercruiser 470 Problems - Please Help

It refuses to even ATTEMPT to start unless it's in Neutral.

I just pulled the motor (bearing or something inside oil pan knocking as the camshaft moves around).

Also gonna try to fix that damn leak.

I also found the reason why it dies on the water: Loose wire. :facepalm:

 

[dccordell]

Re: 1977 Mercruiser 470 Problems - Please Help

When you say "attempt to start", do you mean it doesn't even turn over, or it just never fires?

The neutral safety switch (if exists) will prevent the starter from engaging if the throttle control isn't in neutral.

I have to ask: Are you pushing the little button on the throttle control to give the engine some throttle while cranking, without actually having to put it into gear? I can't think of any other reason you'd want to crank while in gear...

You should be a pro at pulling boat motors soon enough...